Zeolite treating process

ABSTRACT

A novel treated charge zeolite is prepared by treating charge zeolite (which is essentially free of Secondary Pores) with steam for 5-60 hours at 1000° F.-1500° F. Product is particularly characterized by increased Secondary Pore Volume (pores of diameter of 100A-600A) in amount of as high as 0.20 cc/g.

RELATED APPLICATION

This application is a continuation-in-part of application Ser. No.07/368,006, filed June 19, 1989 now abandoned by Texaco Inc. as assigneeof Pei Shing Eugene Dai, David Sherwood, and Bobby Ray Martin.

FIELD OF THE INVENTION

This invention relates to a process for treating a zeolite to modify itsproperties.

BACKGROUND OF THE INVENTION

As is well known to those skilled in the art, zeolite catalysts havebeen used in hydrocarbon processing. Prior art zeolites have been foundto be effective as catalysts for cracking, hydrocracking,hydrosulfurization, etc. Recent trends in resid hydroprocessing demandincreased conversion of feed having a boiling point above 1000° F. aswell as improved hydrogenation selectivity as measured by Conradsoncarbon conversion and hydrodenitrogenation (HDN) of the 1000° F.-products attained from cracking of the residue.

It is an object of this invention to provide a process for treating azeolite to yield a novel treated zeolite catalyst which is characterizedby improved properties. Other objects will be apparent to those skilledin the art.

STATEMENT OF THE INVENTION

In accordance with certain of its aspects, this invention is directed toa process of treating a charge zeolite selected from the groupconsisting of (i) mordenite having a silica to alumina mole ratio ofabout 10-120, (ii) silicalite having a silica to alumina mole ratio ofabout 350-370, and (iii) a dealuminated Y-zeolite having a silica toalumina mole ratio of about 3-10 and a Lattice Constant of about24.30A-24.60A which charge is characterized by the absence of SecondaryPores of diameter of about 100-600A which comprises

contacting said charge zeolite with steam at 1000° F.-1500° F.;

maintaining said charge zeolite in said contact with steam for 5-60hours during which time said charge zeolite is converted into ahydrothermally-treated zeolite characterized by (i) a decreased LatticeConstant of 24.23A-24.38A, (ii) a Secondary Pore Size of 100A-600A,(iii) an increased Secondary Pore Volume of 0.05-0.15 cc/g; and (iv) aSecondary Pore Mode of 100A-325A; and

recovering said hydrothermally-treated zeolite.

DESCRIPTION OF THE INVENTION

The charge zeolites which may be treated by the process of thisinvention are typically characterized by various properties includingpore size, unit cell size, silica to alumina mole ratio, etc.

Primary Pore Size -- The primary pores are small pores characterized bya pore diameter of less than about 100A, and typically 20A-40A, say 23A.These small or micropores are commonly present together with supermicropores having a pore diameter of 40A-100A, say 47A. Pore size ismeasured by nitrogen desorption isotherm.

Primary Pore Volume -- The volume of the primary pores (includingmicropores and super micropores) is typically 0.08-0.14, say 0.11 cc pergram of charge zeolite. Primary Pore Volume is measured by nitrogendesorption isotherm.

Lattice Constant -- The unit cell size (or lattice constant) of thecharge zeolites which may be improved by the process of this inventionis typically above 24.20A; and it may commonly be 24.30A-24.60A, say24.57A. Unit cell size is measured by X-ray diffraction.

Secondary Pore Size -- The secondary pores are large pores characterizedby a pore size (diameter) of greater than 100A, and typically 100A-600A.Secondary pore size is measured by the nitrogen desorption isotherm.

Secondary Pore Volume -- The charge zeolites which may be treated by theprocess of this invention are characterized by a low secondary .porevolume. Typical secondary pore volumes are below 0.05 cc/g and commonlyin the range of 0.02-0.05 cc/g. Thus the charge zeolites may beconsidered as being essentially free of secondary pores. Secondary porevolume is measured by the nitrogen desorption isotherm.

Total Pore Volume -- The total pore volume of the charge zeolites whichmay be treated by the process of this invention may be 0.10-0.12 cc/g,say about 0.10 cc/g (as measured by the nitrogen adsorption isotherm).

Total Surface Area -- The total pore volume of the charge zeolites whichmay be treated by the process of this invention may typically be 600-700m² /g, say 680 m² /g (as measured by Brunauer-Emmett-Teller (BET)Technique).

Crystallinity -- The crystallinity of the charge zeolites which may betreated by the process of this invention may be 85% -1 00%, say 92% (asmeasured by X-ray diffraction).

Silica-to-Alumina Mole Ratio -- The silica-to-alumina mole ratio of thecharge compositions which may be treated by the process of thisinvention may be 6-20, say 8. This is equivalent to asilicon-to-aluminum atom ratio of 3-10, say 4.

Surface Si:Al Atom Ratio --The Surface Si:Al Atom Ratio of the chargezeolite which may be treated by the process of this invention (asmeasured by X-ray photo electron spectroscopy) may be 1.4 -2.5, say 2.0.This is the ratio which prevails over a depth of 50A on the surface ofthe particle.

Acid Site Density --The acid site density of the charge zeolites whichmay be treated by the process of this invention may be 22-32, say 28 ccNH₃ /gram of measured by temperature programmed desorption of ammonia(TPD).

Acid Resistance -- The acid resistance of the charge zeolites which maybe treated by the process of this invention may be 0-30%, say 10% (asmeasured by loss of zeolite crystallinity in contact with a standardacid solution).

The charge zeolites may include a zeolite selected from the groupconsisting of (i) mordenite having a silica to alumina mole ratio of10-120, (ii) silicalite having a silica to alumina mole ratio of350-370, (iii) dealuminated Y-zeolite having a silica to alumina moleratio of 3-10 and a lattice constant of about 24.30-24.60A, which chargeis particularly characterized by the substantial absence of secondarypores of diameter of about 100-600A.

The charge zeolite may include those characterized by a silica toalumina mole ratio of typically 6-20, say 6 and a Lattice Constant ofabout 24.30-24.60A, preferably 24.45A-24.60A, say about 24.57A. When thecharge is mordenite, it may typically be characterized by a silica toalumina mole ratio of 10-120, preferably 10-20, say about 12. When thecharge is a silicalite, it may typically be characterized by a silica toalumina mole ratio of about 350-370, say 350. When the charge is anultrastable Y-zeolite, it 25 may typically have a silica to alumina moleratio of 7-14, preferably 6-8, say about 7. and a lattice constant ofabout 24.50A-24.60A, say 24.57A. When the charge is a super ultrastableY-zeolite, it may typically have a lattice constant of less than about24.50A, typically 24.20-24.48A, preferably 24.30-24.40A, say 24.39A. Theprocess of this invention may be particularly useful when the chargezeolite is a dealuminated zeolite typified by an ultrastable zeolite ora super ultrastable zeolite.

Mordenite is a natural zeolite characterized by a 12-membered ring,tubular pores, and the formula Na₈ (AlO ₂)₈ (SiO ₂)₄₀ 0.24 H₂ O.Silicalite is a zeolite which essentially free of alumina. Faujasite isa natural zeolite characterized by the formula (Ca, Mg, K₂) 29.5 (AlO₂)₅₉ (SiO ₂)₁₅₄ 0.27 H₂ O. Ultrastable zeolites are NH4+exchangeddealuminated Y-zeolites. Super ultrastable zeolites are H+ form ofsteamed ultrastable Y-zeolites.

The charge zeolite may be in the hydrogen form, the ammonium form, orpreferably in an exchanged form i.e. a form in which any alkali metalpresent has been exchanged for e.g. one or more rare earth metals.Alkali metal is present preferably in amount of less than about 0.5 wt.%. The preferred form is the commercial ammonium form.

Illustrative commercially available zeolites which may be treated by theprocess of this invention may include the following, the properties ofwhich are set forth in the table which follows:

TABLE Typical Charge Zeolites

A. The LZ-Y82 brand of Y-zeolite of Union Carbide (an ultrastablezeolite)

B. The Valfor CP 300-56 brand of Y-zeolite of PQ Corp (an ultrastablezeolite)

C. The Valfor CP 300-35 brand of super ultrastable Y-zeolite of PQ Corp

D. The Zelon 900-H brand of mordenite of Norton Company

E. The S- 115 brand of silicalite of Union Carbide

                  TABLE                                                           ______________________________________                                        CHARGE ZEOLITE                                                                Property         A      B      C    D     E                                   ______________________________________                                        Primary Pore Size A                                                                            22     23     85   39    38                                  Primary Pore Volume cc/g                                                                       0.08   0.08   0.11 0.01  0.07                                Lattice Constant 24.51  24.57  24.35                                                                              --    --                                  Secondary Pore Mode A                                                                          none   none   none none  none                                Secondary Pore Volume cc/g                                                                     0.02   0.02   0.12 0.004 0.003                               Total Pore Volume cc/g                                                                         0.10   0.11   0.23 0.02  0.07                                Total Surface Area m.sup.2 /g                                                                  626    683    580  413   404                                 Crystallinity %  100    100    87   95    99                                  SiO.sub.2 to Al.sub.2 O.sub.3                                                 Mole Ratio (XRD) 8      6      8    Ca 12 350                                 Acid Site Density cc/g                                                                         26.2   28.9   6.5  7.0   2.3                                 Acid Resistance %                                                                              20     0      --   --    --                                  ______________________________________                                    

The preferred charge zeolite is a zeolite such as the LZ-Y82 brand ofY-type zeolite of Union Carbide.

It is a feature of the process of this invention that the charge zeoliteis contacted with steam at 1000° F.-1500° F., preferably 1300-1450° F.,say about 1400° F. Preferably the steam employed should contain littleor no other gases such as an carbon dioxide, oxygen, nitrogen, etc. Inthe preferred embodiment, the steam will be substantially 100% steami.e. it contains less than about 10 wt. % of non-steam components. It isfound that presence of non-steam components in amount greater than about10 wt. % is undesirable because it slows down the reaction.

Although operation at temperature slightly below about 1000° F. (saydown to about 800° F.) may be employed, it is found that the desiredresults are attained to a lesser degree. At temperature of about 600° F.or less, the desired changes may not be attained to any desired degree.Operation at temperature above about 1500° F. undesirably increases thecost of operation; and as the temperature rises above this level, thereis increasing chance of deactivating the catalyst.

The charge zeolite is maintained at the noted temperature for 5-60hours, say 16-36, say about 16 hours. Operation below the lower end ofthis range does not yield significant improvement; and operation abovethe upper end of the range normally yields little or no additionalimprovement. It is found that the desired degree of improvement (asmeasured for example by the increase in the secondary pore volume) istypically obtained after about 16-24 hours. Typically the improvementbecomes asymtotic after about 16 hours.

At the conclusion of the desired contacting with steam for 5-60 hours at1000° F. -1500° F., the treated zeolite is recovered and cooled toambient temperature.

The characteristics of the treated zeolite may be as follows:

Primary Pore Size -- The primary pore size is typically 20A-100A, sayabout 47A (for the super micropores). Thus it may be observed that thereis no significant change in primary pore size.

Primary Pore Volume -- The primary pore volume is typically 0.04-0.13,say about 0.08 cc/g. Thus it may be observed that there is nosignificant change in primary pore volume.

Lattice Constant -- The unit cell size (or lattice constant) of thetreated zeolite is unexpectedly decreased to as low as 24.23A andtypically to 24.23A-24.38A, preferably 24.23-24.29A, typically24.24-24.27A, say 24.26A. This may represent a desired decreased by0.07-0.35A, say 0.31A.

Secondary Pore Size -- The secondary pore size of the treated zeolite istypically 100-600A and commonly 105A-190A.

Secondary Pore Volume of the treated zeolite is 0.05-0.15, say 0.14cc/g. It is unexpected that the secondary pore volume may increase by50% -600%, say 300% over the secondary pore volume of the chargezeolite. (The charge zeolite is particularly characterized by theabsence of secondary pores).

Secondary Pore Mode -- When the Secondary Pore Volume (in cc/g isplotted as a function of the Secondary Pore Size (the diameter of thePores in Angstrom Units) in the 100Å-600Å range which defines theSecondary Pores, the resulting curve has its largest value (or peak ormaximum) at a point which is called the mode. More specifically the Modeis the value of Pore Size at which the curve has a maximum. Specificallythe Secondary Pore Mode is the value of the Secondary Pore Size at whichthe Secondary Pore Volume is a maximum (in the 100Å-600Å Pore Size rangewhich characterizes the Secondary Pores). Typically the Secondary PoreMode of the treated product may be above 100A, and commonly about105A-325A, 25A, typically 135A.

Total Pore Volume -- The pore volume of the treated zeolite is 0.16-0.23cc/g, say 0.20 cc/g which may unexpectedly be 50%-120%, say 90% greaterthan the total pore volume of the charge zeolite.

Total Surface Area -- The total surface area of the treated zeolite is350-600 m² /g, say 450 m² /g.

Crystallinity - The crystallinity of the treated zeolite is 60%-85%, say70%.

Silica-to-Alumina Mole Ratio -- The silica-to-alumina alumina mole ratioof the treated zeolite is 22-54, say 46. This corresponds to asilicon-to-aluminum atom ratio of 6-27, say 23.

Surface Silicon-to-Aluminum Atom Ratio (in the outer 50A layer) TheSi:Al surface ratio of the treated zeolite is 0.8-16, typically 0.9-1.3,say 1.0.

Acid Site Density -- The acid site density of the treated zeolite is1-10, say 6.

Acid Resistance -- The acid resistance of the treated zeolite is 90-120,say 100.

It will thus be apparent that the treated zeolite is particularlycharacterized by (i) the creation of secondary pores of diameter ofabout 100A-600A from a charge zeolite which is essentially free ofsecondary pores, (ii) a decrease in the unit cell size (or latticeconstant), (iii) a decrease in the crystallinity (zeolite content) and(iv) an increase in the silica-to-alumina ratio. These treated zeolitesare also characterized by (i) a primary pore size and volume which isessentially comparable to that of the charge zeolite, (ii) an decreasein total surface area, (iii) a decrease in acid site density and (iv) anincrease in acid resistance.

It is a particular feature of the process of this invention that, at agiven temperature, as the steaming time increases, the Secondary PoreVolume and Secondary Pore Mode increase; and at about 16 hours, theybecome asymptotic. It is observed that, at a time below about 5 hoursthe maximum Secondary Pore Volume is undesirably low (e.g. below about0.05 cc/g); and the Pore Mode is also undesirably low (e.g. below about100A). cf. US 4,477,336 to Harshaw/ Filtrol as assignee of J. Scherzer.It is also a feature of this invention that, after a steaming time ofabout 5 hours, the Total Pore Volume and the Pore Mode becomeessentially an increasing function of temperature.

It is a feature of the treated zeolites of this invention (typicallypresent in particles of particle size of 0.2-2 microns) that they may bemixed with suitable binders, such as silica or alumina to form a mixcontaining 10-90 wt. % zeolite. This mix may be extruded, dried at 250°F.-400° F., say 350° F., for 0.hour-12 hours, preferably 0.2-8 hours,say 4 hours, calcined at 1100° F.-1400° F., say 1200° F. for 0.5-2hours, say 1 hour and impregnated with metals which are useful as H-Oilcatalysts -- typically Ni-Mo, Co-Mo, Ni-Mo-P, Co-Mo-P, etc.

A typical such catalyst may contain 0.5-4 wt. %, say 2.7 wt. %, Ni and3-15 wt. %, say 10 wt. % Mo on a 1 mm diameter particle containing 80wt. % alumina and 20 wt. % treated zeolite.

This catalyst may be used in a hydrotreating process. Typically in ahydrotreating process (such as the H-Oil brand of process), reaction iscarried out in an ebullated bed reactor containing particulate catalyst.Temperature of operation may be 650° F.-850° F., preferably 750° F.-850°F., say 805° F. at 1000-4000 psig, preferably 2000-3000 psig, say 2500psig. Space velocity is sufficient to maintain the bed of particulatecatalyst in an expanded state. Hydrogen is admitted, with the chargehydrocarbon, in amount of 1000-50,000 SCFB, preferably 5000-10,000 SCFB.

Typical H-Oil feed is an atmospheric reduced crude or a vacuum bottoms;and commonly 75% of the feed boils above 1000° F. It typically maycontain 1-10 wt. % sulfur and up to 1000 ppm metals (including nickeland vanadium).

H-Oil product is characterized as a liquid product of lower density andaverage boiling point, lower sulfur content, and lower content ofmetals.

It is also a feature of the zeolite product of this invention that itmay be useful as a catalyst in hydrocarbon cracking as in a fluidcatalytic cracking process wherein hydrocarbon charge, such as a gasoil, is cracked at 900° F.-1100° F., typically 960° F. at 0-20 psig, say0 psig. It is found that the novel catalyst of this invention may beparticularly effective in cracking the 900+° F. ibp fraction of chargegas oils. As determined by the slurry oil in the cracked product (i.e. %of the oil boiling at least as high as 670° F.) the zeolite catalyst ofthis invention desirably yields crackate having typically 10% less ofthe slurry oil than prior art zeolites. This is believed to be due tothe presence of an increased volume of Secondary Pores (which istypically 0.05-0.15 cc/g, as distinguished from prior art zeolites whichare essentially free of Secondary Pores) and an increased Secondary PoreMode (which is typically 105-190A as distinguished from prior artzeolites which do not have a Secondary Pore Mode -because of the absenceof Secondary Pores).

DESCRIPTION OF SPECIFIC EMBODIMENTS

Practice of the process of this invention will be apparent to thoseskilled in the art from the following wherein all parts are parts byweight unless otherwise stated. An asterisk indicates a control example.

EXAMPLE I

In this example, which represents the best mode presently known ofcarrying out the process of this invention, the charge zeolite is theValfor CP300-5 brand of ultrastable Y-type zeolite (in ammonium form) ofPQ Corp. This Y-zeolite is characterized by the properties set forth inthe table infra.

In this example, the zeolite is contacted with essentially 100% steamfor 24 hours at 1400° F. This charge zeolite and the treated zeolite atthe end of the treating period are characterized as in the followingtable:

                  TABLE                                                           ______________________________________                                                                    Steam                                                                 Charge  Treated                                           Property            Zeolite Zeolite                                           ______________________________________                                        Primary Pore Size A 23      47                                                Primary Pore Volume cc/g                                                                          0.08    0.07                                              Lattice Constant A  24.57   24.26                                             Secondary Pore Mode A                                                                             None    135                                               Secondary Pore Volume cc/g                                                                        0.02    0.14                                              Total Pore Volume cc/g                                                                            0.11    0.20                                              Total Surface Area m.sup.2 /g                                                                     683     456                                               Crystallinity %     100     70                                                SiO.sub.2 to Al.sub.2 O.sub.3 Mole Ratio                                                          6       46                                                Acid Site Density % 28.9    6                                                 Acid Resistance %   0       100                                               ______________________________________                                    

Preparation of catalyst from this treated zeolite may be carried out bymixing 20 parts of zeolite and 80 parts of gamma alumina, extruding toform l mm X 6mm cylinders, drying at 350° F. for 4 hours, calcined at1200° F. for one hour, and then loading. The particles are loaded byimmersing in nickel nitrate solution for 24 hours, drying at 250° F. for4 hours, and calcining at 1200° F. for one hour. The particles are thenimmersed in aqueous ammonium molybdate solution for 24 hours, dried at350° F. for 4 hours, and calcined at 1200° F. for one hour.

This catalyst may be employed in an H-Oil process to which is charged anArabian Medium/Heavy Vacuum Resid having the following properties:

                  TABLE I                                                         ______________________________________                                        Typical Petroleum Feedstock                                                   (Arabian Medium/Heavy Vacuum Resid)                                           ______________________________________                                        API Gravity        4.8                                                        1000° F.+, vol %                                                                          87.5                                                       1000° F.+, wt %                                                                           88.5                                                       Sulfur, wt %       5.0                                                        Total Nitrogen, wppm                                                                             4480                                                       Hydrogen, wt %     10.27                                                      Carbon, wt %       84.26                                                      Alcor MCR, wt %    22.2                                                       Kinematic Viscosity, cSt                                                      @ 212 F            2430                                                       @ 250 F            410                                                        @ 300 F            117                                                        Pour Point, °F.                                                                           110                                                        n-C.sub.5 Insolubles, wt %                                                                       28.4                                                       n-C.sub.7 Insolubles, wt %                                                                       9.96                                                       Toluene Insolubles, wt %                                                                         0.02                                                       Asphaltenes, w %   9.94                                                       Metals, wppm                                                                  Ni                 49                                                         V                  134                                                        Fe                 10                                                         Cu                 3                                                          Na                 49                                                         Chloride, wppm     28                                                         ______________________________________                                    

Charge may be admitted in liquid phase at 770° F. and 2250 psig to anebullated bed of catalyst. Space velocity LHSV is 0.56. Hydrogen isadmitted in amount of 7000 SCFB.

Hydrocarbon product may be characterized by increased production ofliquid boiling below 1000° F.

EXAMPLES II-VIII

In order to determine the effect of steaming time at 1420° F. on thecharge LZ-Y82 brand of ultrastable zeolite, several runs were carriedout in which the zeolite content, the Si:Al ratio, and the latticeconstant of the steamed (hydrothermally treated) zeolite inter alia weredetermined as a function of the time of steaming. The results aretabulated as follows:

                                      TABLE                                       __________________________________________________________________________                          SiO.sub.2                                                                              Sec  Surf                                                 Sec        Al.sub.2 O.sub.3                                                                       Pore Vol                                                                           Si:Al                                          Steaming                                                                            Pore Zeolite                                                                             Mole                                                                              Lattice                                                                            100-600A                                                                           Atom                                      Example                                                                            Time Hrs.                                                                           Mode A                                                                             Content %                                                                           Ratio                                                                             Cons. A                                                                            cc/g Ratio                                     __________________________________________________________________________    II*   0     47  100    8  24.51                                                                              0.02 1.5                                       III*  2     78  87    16  24.38                                                                              0.05 1.0                                       IV    8    105  80    26  24.31                                                                              0.07 0.9                                       V    16    145  62    46  24.26                                                                              0.10 0.9                                       VI   24    125  66    54  24.25                                                                              0.11 0.9                                       VII  24    125  64    46  24.26                                                                              0.10 0.9                                       VIII 48    125  61    40  24.27                                                                              0.12 0.9                                       __________________________________________________________________________

From these Examples, it is apparent that, as the steaming timeincreases;

(i) the zeolite content (i.e. Crystallinity) of the treated productdrops to a level of about 60-65%;

(ii) the SiO ₂ :Al₂ O ₃ Mole Ratio (as determined by XRD) increases toabout 40-54 at which point it levels off i.e. the zeolite becomesdealuminated

(iii) the Surface Si:Al atom ratio drops from 1.5 down to 0.9 indicatingthat the surface becomes aluminum-enriched.

(iv) the Lattice Constant drops to as low as 24.25A;

(v) the Secondary Pore Volume of the treated product increases to about0.12 (an increase by a factor of 6); and

(vi) the Secondary Pore Mode increase from 47 up to about 125;

(vii) a point is reached after about 16-24 hours after which nosignificant change appears to occur.

EXAMPLES IX-XII

In a further series of runs, the charge zeolite of Example I is steamedfor 24 hours at different tempera-tures, and the pore volumes aremeasured in addition to other criteria reported below:

                  TABLE                                                           ______________________________________                                        Desorption Pore Volume Distribution                                                                                Pore                                     Example Temp °F.                                                                          20-100A   100-600A                                                                              Mode A                                   ______________________________________                                        IX      1350       0.10      0.07    105                                      X       1420       0.08      0.10    115-125                                  XI      1450       0.07      0.12    145                                      XII     1470       0.07      0.09    170                                      ______________________________________                                    

It is apparent from the above table that, as the steaming temperatureincreases within the desired range of 1000° F.-1500° F., the volume ofpores in the 20-100A range decreases; and the volume of pores in thesecondary pore size range (100-600A) increases.

                  TABLE                                                           ______________________________________                                                   Example                                                                       Steaming Temp.                                                                  IX       X        XI     XII                                     Property     1350° F.                                                                        1420° F.                                                                        1450° F.                                                                      1470° F.                         ______________________________________                                        Zeolite Content %                                                                          64       65       58     60                                      SiO.sub.2 /Al.sub.2 O.sub.3, Mole                                                          46       46       64     64                                      Ratio (XRD)                                                                   Lattice Constant A                                                                         24.26    24.26    24.24  24.24                                   Surface Si:Al Atom                                                                         0.9      0.8      0.8    0.8                                     Ratio (XPS)                                                                   Surface Area m.sup.2 g                                                                     457      411      392    376                                     Total Pore Volume                                                                          0.17     0.19     0.16   0.19                                    cc/g                                                                          ______________________________________                                    

EXAMPLES XIII-XVII

In this series of Examples, the procedure of Examples I-VIII is followedusing as the charge Y-zeolite the Valfor CP 300-56 brand of UltrastableY-zeolite in ammonium form of PQ Corp characterized by the propertiesset forth in the text supra.

                                      TABLE                                       __________________________________________________________________________                              SiO.sub.2 :                                                                       Surf                                                       Secondary      Al.sub.2 O.sub.3                                                                  Si:Al                                                                              Secondary                                       Steaming                                                                            Pore       Mole                                                                              Atom                                                                              Lattice                                                                            Pore Vol                                   Example                                                                            Time Hrs.                                                                           Mode A                                                                              Cryst. %                                                                           Ratio                                                                             Ratio                                                                             Cons. A                                                                            100-600A                                   __________________________________________________________________________    XIII*                                                                              0      47   127   8  1.8 24.54                                                                              0.05                                       XIV* 0      43   123   6  2.0 24.57                                                                              0.02                                       XV   8     115   85   40  1.0 24.27                                                                              0.13                                       XVI  24    190   69   40  0.9 24.27                                                                              0.19                                       XVII 28    325   57   40  1.0 24.27                                                                              0.11                                       __________________________________________________________________________

Crystallinity in this table is relative to that of the commerciallyavailable LZ Y-82 zeolite.

EXAMPLES XYIII-XXVII

In this series of Examples, the procedure of Example I-VIII isduplicated using as charge the CP30056 brand ultrastable Y-zeolitecatalyst.

                  TABLE                                                           ______________________________________                                                                       Secondary                                               Steaming     Pore     Pore Vol %                                     Example  Time Hrs.    Mode A   100-600A                                       ______________________________________                                        XVIII*    0            43      0.02                                           XIX*      5           135      0.12                                           XX        8           125      0.13                                           XXI      16           145      0.14                                           XXII     24           170      0.17                                           XXIII    48           190      0.20                                           ______________________________________                                    

It will be noted that the composition of this Table (unlike that ofExample II-VIII) is characterized by a Pore Mode and a Secondary PoreVolume which unexpectedly do not level off as they do in ExamplesII-VIII with an increase in steaming time beyond 16 hours. This providesflexibility in adjusting a product catalyst so that it may be preparedto maximize effectivity for removal of asphaltenes or removal of sulfur,each of which may be most effectively accomplished at different PoreModes or Secondary Pore Volumes.

EXAMPLES XXIV-XXIX

In this series of Examples, the procedure of Examples II-VIII isduplicated except that the temperature of steaming is 1470° F. insteadof 1420° F.

                                      TABLE                                       __________________________________________________________________________                         SiO.sub.2                                                                         Sur                                                                       Al.sub.2 O.sub.3                                                                  Si:Al    Sec                                              Steaming                                                                            Pore      Mole                                                                              Atom                                                                              Lattice                                                                            Pore Vol                                    Example                                                                            Time Hrs.                                                                           Mode A                                                                             Crysta %                                                                           Ratio                                                                             Ratio                                                                             Cons. A                                                                            100-600A                                    __________________________________________________________________________    XXIV*                                                                              0      47  100   8  1.5 24.51                                                                              0.02                                        XXV* 2      98  80   28  0.9 24.30                                                                              0.05                                        XXVI 5     110  69   54  0.8 24.25                                                                              0.10                                        XXVII                                                                              8     125  67   54  0.8 24.25                                                                              0.12                                        XXIX 24    190  60   64  0.8 24.24                                                                              0.10                                        __________________________________________________________________________

EXAMPLES XXX-XXXVIII

In the series of Examples, the procedure of Examples IX-XII is employedexcept that the zeolite charge is the Valfor CP300-56 brand ofUltrastable zeolite in ammonium form of PQ Corp which is steamed for 24hours at the noted temperature.

                                      TABLE                                       __________________________________________________________________________                     SiO.sub.2                                                                     Al.sub.2 O.sub.3                                                                        Pore Secondary                                          Steaming                                                                            Zeolite                                                                             Mole                                                                              Lattice                                                                             Mode Pore Vol %                                    Example                                                                            Temp °F.                                                                     Content %                                                                           Ratio                                                                             Constant A                                                                          A    100-600A                                      __________________________________________________________________________    XXX* Untreated                                                                           100    6  24.57  23,43                                                                             0.02                                          XXXI 1100  82    16  24.38  43,115                                                                            0.16                                          XXXII                                                                              1250  78    26  24.31 115-125                                                                            0.17                                          XXXIII                                                                             1350  74    32  24.29 115-125                                                                            0.17                                          XXXIV                                                                              1400  61    46  24.26 135,170                                                                            0.20                                          XXXV 1420  65    46  24.26 145,165                                                                            0.16                                          XXXVI                                                                              1450  63    64  24.24 145,170                                                                            0.21                                          XXXVII                                                                             1470  58    18  24.24 145,170                                                                            0.18                                          __________________________________________________________________________

From the above table, it will be apparent that the process of thisinvention permits attainment of zeolite which is dealuminized and whichis characterized by an aluminum-enriched surface and by partialdestruction of the zeolite crystal structure and by increased secondaryporosity (i.e. pores in the 100-600A region). These products containdomains of high thermal and hydrothermal stability separated by holes oramorphous domains which contribute to the decrease of the averagecrystalline fraction. Non-framework alumina and silica-alumina createdduring the hydrothermal stabilization process may be present in theintracrystalline voids or included in the retained crystalline frameworkstructure.

It is a characteristic of the products of the process of this inventionthat they contain secondary pores of about 105-190A size, that the porevolume of pores of diameter of 100-600A may be increased by 0.05-0.15cc/g, that the surface of the treated zeolite is enriched with respectto aluminum, that the total acid site density may be decreased, and thatthe treated zeolite may be characterized by increased enhancement inacid resistance.

EXAMPLE XXXVIII

In this Example, which shows use of the product zeolites of thisinvention in fluid catalytic cracking (FCC), the catalyst tested is thepure zeolite of Example XX (in hydrogen form). The charge hydrocarbon isa high nitrogen Vacuum Gas Oil into which has been blended atmosphericresid. This charge has an ibp of 484° F., a 50% b.p. of 780° F., and a95% bp of 993° F. It is characterized by a slurry oil content (i.e.% ofcharge which is characterized by a boiling point above 670° F.) of 82%.

Operating conditions include 960° F. at 0 psig; and catalyst-to-oilratio is 3 and the WHSV is 32.

Cracked product is characterized by a slurry oil content of 56%. It isapparent that the slurry oil content has been desirably decreased from82% down to 56%. Typical prior art zeolites give a slurry oil content ofabout 72%.

Although this invention has been illustrated by reference to specificembodiments, it will be apparent to those skilled in the art thatvarious charges and modifications may be made which clearly fall withinthe scope of the invention.

We claim:
 1. A process of treating a charge zeolite selected from thegroup consisting of (i) mordenite having a silica to alumina mole ratioof about 10-120, (ii) silicalite having a silica to alumina mole ratioof about 350-370, and (iii) dealuminated Y-zeolite having a silica toalumina mole ratio of about 3-10 and a Lattice Constant of about24.30A-24.60A, which charge is characterized by the absence of secondarypores of diameter of about 100-600A which comprisescontacting saidcharge zeolite with steam at 1000° F.-1500° F.; maintaining said chargezeolite in said contact with steam for 5-60 hours during which time,said charge zeolite is converted into a hydrothermally-treated zeolitecharacterized by (i) decreased Lattice Constant of 24.23A-24.38A, (ii) aSecondary Pore Size of l00A-600A, (iii) an increased Secondary PoreVolume of 0.05-0.15 cc/g and (iv) a Secondary Pore Mode of 100A-325A;and recovering said hydrothermally-treated zeolite.
 2. A process oftreating a charge zeolite as claimed in claim 1 wherein said chargezeolite is a dealuminated Y-zeolite having a silica to alumina moleratio of about 3-10.
 3. A process of treating a charge zeolite asclaimed in claim 1 wherein said charge zeolite is a mordenite having asilica to alumina mole ratio of about 10-120.
 4. A process of treating acharge zeolite as claimed in claim 1 wherein said charge zeolite is asilicalite having a silica to alumina mole ratio of about 350-370.
 5. Aprocess of treating a charge zeolite as claimed in claim 1 wherein saidcontacting with steam is carried out at 1300° F.-1450° F.
 6. A processof treating a charge zeolite as claimed in claim 1 wherein saidcontacting with steam is carried out at about 1400° .
 7. A process oftreating a charge zeolite as claimed in claim 1 wherein said contactingwith steam is carried out for 16-36 hours.
 8. A process of treating acharge zeolite as claimed in claim 1 wherein said contacting with steamis carried out for about 16 hours.
 9. A process of treating a chargedealuminated ultrastable Y-zeolite in ammonium form having a silica toalumina mole ratio of 7-14 and a lattice constant of 24.50A-24.60A whichcomprises contacting said charge zeolite with steam at 1300° F.-1450°F.;maintaining said charge zeolite in said contact with steam for 16-36hours during which time said charge zeo-lite is converted into ahydrothermally-treated zeolite characterized by (i) a decreased unitcell size of 24.23-24.38A, (ii) a Secondary Pore Size of 100A-600A,(iii) an a Secondary Pore Volume of 0.05-0.15cc/g, and (iv) a SecondaryPore Mode of 100A-325A; and recovering said hydrothermally-treatedzeolite.
 10. A novel zeolite characterized by (i) a lattice constant ofabout 24.23A-24.38A, (ii) a Secondary Pore Size of 100A-600A, (iii) anincreased Secondary Pore Volume of 0.05-0.15 cc/g and (iv) a SecondaryPore Mode of 100A-325A.
 11. A novel hydrothermally treated, dealuminatedY-zeolite characterized by (i) a Lattice Constant of 24.23A-24.38A, (ii)a Secondary Pore Size of 100A-600A, (iii) an increased Secondary PoreVolume of 0.05-0.15 cc/g, and (iv) a Secondary Pore Mode of 100-325A.12. A novel hydrothermally treated, dealuminated Y-zeolite as claimed inclaim 11 wherein said decreased Lattice Constant is 24.23A-24.29A.
 13. Anovel hydrothermally treated, dealuminated Y-zeolite as claimed in claim11 wherein said dealuminated Y-zeolite is prepared from a chargemordenite having a silica to alumina mole ratio of about 10-120.
 14. Anovel hydrothermally treated, dealuminated Y-zeolite as claimed in claim11 wherein said dealuminated Y-zeolite is prepared from a chargesilicalite having a silica to alumina mole ratio of about 350-370.
 15. Anovel hydrothermally treated, dealuminated Y-zeolite as claimed in claim11 wherein said dealuminated Y-zeolite is prepared from a chargedealuminated ultrastable Y-zeolite having a silica to alumina mole ratioof 7-14.
 16. A novel hydrothermally treated, dealuminated Y-zeolite asclaimed in claim 11 wherein said dealuminated Y-zeolite is prepared froma charge dealuminated super ultrastable Y-zeolite having a LatticeConstant of about 24.30A-24.60A.
 17. A novel hydrothermally treateddealuminated zeolite prepared by the process which comprises contacting,with steam at 1000° F.-1500° F. a charge zeolite selected from the groupconsisting of (i) mordenite having a silica to alumina mole ratio ofabout 10-120, (ii) silicalite having a silica to alumina mole ratio ofabout 350-370, (iii) dealuminated Y-zeolite having a silica to aluminamole ratio of about 3-10 and a Lattice Constant of about 24.30A-24.60A,which charge is characterized by the absence of secondary pores ofdiameter of about 100-600A,maintaining said charge zeolite in saidcontact with steam for 5-60 hours during which time, said charge zeoliteis converted into a hydrothermally-treated zeolite characterized by (i)decreased Lattice Constant of 24.23A-24.38A, (ii) a Secondary Pore Sizeof 100A-600A, (iii) a Secondary Pore Volume of 0.05-0.15 cc/g and (iv) aSecondary Pore Mode of 100A-325A; and recovering saidhydrothermally-treated zeolite.